This relates generally to imaging systems, and more particularly to imaging systems with light shields to reduce optical crosstalk.
Image sensors are commonly used in electronic devices such as cellular telephones, cameras, and computers to capture images. In a typical arrangement, an electronic device is provided with an array of image pixels and one or more lenses that focus image light onto the array of image pixels. Circuitry is commonly coupled to each pixel column for reading out image signals from the image pixels.
In conventional imaging systems, stray light and optical crosstalk can cause unwanted image artifacts such as veiling glare, local flare, and reduced quantum efficiency. For example, light may enter an imaging system and may be reflected back and forth between surfaces of lens elements in the imaging system before finally reaching the array of image pixels. In other situations, stray light may enter the imaging system at a high angle of incidence and may be directed on an unintended path, leading to optical crosstalk. This type of stray light and optical crosstalk can cause bright streaks, reduced contrast, and, in some cases, undesirable color tints in dark regions of an image.
It would therefore be desirable to be able to provide imaging systems with reduced optical crosstalk and improved quantum efficiency.